A Simulated Annealing method to solve a generalized maximal covering location problem

The maximal covering location problem (MCLP) seeks to locate a predefined number of facilities in order to maximize the number of covered demand points. In a classical sense, MCLP has three main implicit assumptions: all or nothing coverage, individual coverage, and fixed coverage radius. By relaxing these assumptions, three classes of modelling formulations are extended: the gradual cover models, the cooperative cover models, and the variable radius models. In this paper, we develop a special form of MCLP which combines the characteristics of gradual cover models, cooperative cover models, and variable radius models. The proposed problem has many applications such as locating cell phone towers. The model is formulated as a mixed integer non-linear programming (MINLP). In addition, a simulated annealing algorithm is used to solve the resulted problem and the performance of the proposed method is evaluated with a set of randomly generated problems

The Regenerative Effect of Intra-Articular Injection of Autologous Fat Micro-Graft in Treatment of Chronic Knee Osteoarthritis

The study started in 2010 to find the effect of autologous fat micrograft for osteoarthritis (OA); the result was published on normal animal’s model, in 10 patients, then in 80 patients with knee osteoarthritis, and the current study in 205 patients. The study was conducted at King Abdulaziz University Hospital (January 2012–October 2015); 80 adult patients were suffering from moderate to severe knee osteoarthritis. About 10–20 mL fat micrograft was prepared with liposuction and injected intra-articularly into the affected knee/s. The results revealed that pain improvement after the fat injection during rest and with activity with the visual analogue scale. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) indicated improvement, both in the three domains (pain, stiffness, and physical function) and in total. The use of intra-articular autologous fat micrograft is simple, safe, and effective for degenerative knee osteoarthritis

VNToR: Network Virtualization at the Top-of-Rack Switch

Cloud providers typically implement abstractions for net- work virtualization on the server, within the operating sys- tem that hosts the tenant virtual machines or containers. Despite being flexible and convenient, this approach has funda- mental problems: incompatibility with bare-metal support, unnecessary performance overhead, and susceptibility to hypervisor breakouts. To solve these, we propose to offload the implementation of network-virtualization abstractions to the top-of-rack switch (ToR). To show that this is feasible and beneficial, we present VNToR, a ToR that takes over the implementation of the security-group abstraction. Our prototype combines commodity switching hardware with a custom software stack and is integrated in OpenStack Neutron. We show that VNToR can store tens of thousands of access rules, adapts to traffic-pattern changes in less than a millisecond, and significantly outperforms the state of the art

Investigation of plant extracts for antimicrobial activity

Available from British Library Document Supply Centre-DSC:DXN015460 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

A logic-based Benders decomposition method for the multi-trip traveling repairman problem with drones

This paper considers the problem of delivering a certain number of packages to a set of customers using multiple drones dispatched from a single truck. Once a drone delivers a package, it returns to the truck to pick up another package while the truck waits at the launch location. The aim is to determine the truck route and the sequence of drone trips from the truck such that all the customer demands are served, either by the truck or drones, to minimize the sum of customer waiting times. We propose a new formulation of this problem based on an extended graph network representation. A new logic-based Benders decomposition method enhanced with relaxations is also developed and evaluated on several benchmark instances. The numerical results show that the proposed exact method obtains optimal solutions to the majority of the problem instances within the time limit of one hour